Willabd i



Patented Nov. 28, 1922.

PATENT OFFICE.

WILLARD I. TW'OMBLY, OF NEWARK, NEW JERSEY.

LIQUID-FEEDING MEANS AND METHOD.

Application filed March 27, 1920, Serial No, 369,380. Renewed July 10, 1922.

To all whom it may concern Be it known that I, VILLARD I. TwoMBLY, a citizen of the United States, and resident of Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Liquid Feeding Means and Methods, of which the following is a specification.

This invention relates to means for feeding liquid, as for instance, liquid fuel or gasoline, from a source'of supply to a reservoir and to the intake of an engine such as the carbureter of an internal combustion engine.

The device, as shown herein, is adapted for the same general purposes, and embodies, in a new way, certain of the features of construction and operation set forth in my prior application, Serial No. 197,589, filed October 20th, 1917.

The general purpose of the invention is to provide improved liquid pumping means operable from the movements of the engines, which means are simple and cheap in construct-ion and efficient in operation.

Heretofore, in apparatus of this character, it has been the practice to connect a reservoir to theintake manifold of an engine and to utilize the suction of the piston of the engine to apply a vacuum directly to the surface of the fuel in the reservoir. There have also been attempts to employ a diaphragm pump directly connected but such attempts have been practical failures for many reasons which will become evident from a consideration of my practical, foolproof device herein disclosed.

One object of this invention is to provide a pump having a pump element operable by a wide range of varying pressures and speeds of the engine; and an important feature is employing as the pumping element, a projectile or freely movable, spring returned piston.

The pump is preferably associated with a reservoir having the pump located therein and preferably extending therethrough. Preferably the reservoir is cylindrical and has the pump cylinder axially disposed therein, the pump cylinder is vertically arranged, preferably the intake for the liquid opens upwardly into the lower end of the said cylinder. Preferably Serial No. 573,925.

cylinder; the outlet intothe reservoir is through the lateral wall of said cylinder; and the. inlet for application of pressure from the combustion chamber of the engine, is through a constriction at the upper end the pump .cylinder is rigidly secured water-tight, through the bottom of the reservoir and the upper end ofthe pump projects through and serves as securing means for clamping the cover or closure on said vessel.

Several important features of the invention relate to making it successfully operative under certain conditions likely to arise in practical operation of the device, as for instance, when there is no liquid in the supply line because the tank has become empty, or the pump valves have leaked. To meet such conditions, it is important-the pump be able to act effectively as an air pump to vacuumize the line and draw up the liquid,

and, for subsequent successful operation atv high speeds of the engine, it is necessary that the last remnants of air be expelled from the pump cavity so that the piston will act on an incompressible body of fluid, namely, all liquid, without any trapped air or gas.

For effective air. pumping the inlet valve j into the pump chamber is preferably an upwardly-opening, gravity-seated ball. and, in order to avoid trapping air, the inlet passage opens upwardly.

The port through which the liquid is expelled from the pump cavity and the outlet valve therefor have certain peculiarities particularly adapting them to serve both the above purposes. The outletport opens upwardly from the topmost portion of the pump cavity which, in this case, is the pump face of the piston, so that any air or other.

gas rising to the top of the liquid. will be automatically pumped out and expelled into the reservoir, thus leaving only incompressible liquid for action of the pump at high speeds.

Preferably, the outlet valve is also located in the piston and is arranged to lift and seat in alignment with the reciprocating movements of the piston, so that the inertia of the outlet valve is caused to assist in seating it at the end of each expelling outstoke and speeds of which are free from control by any rigidly acting driving connection, and the starts and stops must occur as often as 4 or 5 times per second, for idling speeds, up to'say 80 to 100 or more times per second, for high speeds. Moreover, the selfseating inertia effect will be greatest when it is most needed, that is when the engine speeds are highest, and also when the piston is pumping air. .The air is relatively ineffici'ent for seatingand unseating the valve,

but since it affords enormously less resistance to the piston, it promotes higher piston velocities, thereby making inertia more effective in its seating and u'nseating action.

By making the'piston chamber long as compared with the normal or average stroke of the" piston, and the springs for returning the piston correspondingly long the'pump is rendered automatically selfaccommodating for awide range of engine pressures and speeds.

The several improvements above described result in a pump that is capable of operating at all, times under all conditions ofuse of the engine, from mere cranking to start the engine, up to the highest 0 crating speeds, or lightest to heaviest loa s.

A Sf a result, I am able to reduce the size and capacity of the reservoir down to a point where it needbe no more than a pressure equalizing chamber to steady the lnte'r'mittent sup 1y of liquid afiorded by the strokes. of the continuously operating pump; The pump. delivers continuously a supply of liquid greater than the engine can use and the excess is returned to the tank.

In this, connection an important feature of my invention consists in hermetically sealing the u per part of the reservoir to establish a ontinuous internal pressure driving the excess liquid back through the overflow standpipe, to the supply tank. This latter feature of pressurereturn of the overflow excess is of greatest practical importance since it makes possible the employing of a small inexpensive returnpipe, whereas a gravity overflow return would require a much larger, prohibitively expensive pipe. Moreover, the troublesome and expensive floats and control valves are dispensed with as also the vent in the top of thereservoir which so commonlyoperates to permit escape of. gasoline whenever the of when is theusual variah1e-throttle,'vari from a tank and deliver it to the carbure ter of an engine, the tank being located at a point below the carbureter;

Figure 2 is a sectional side elevation of an embodiment of a pumping combined with a'pressure chamberforte in connection with my improved fuel or gasoline feeding means. InFigure 1 of the drawings, I have shown an embodiment ofr'ny invention ap plied as a fuel' or gasoline "feed informed tion with a motor vehicle, the motive power able-speed internal ombusti pen ine 910 which is connected a carburetor" 10 by 'a manifold 11. A fuel or gasoline su" ply ki a ocaed a th r a Q he .wls at a point below the carbureter, with. improved means (designated in a. general way by P) to draw thefiietfrom the and deliver it to the carbureter of the. intake of the engine in pesitionbetweensaid tank and" carbureter, the tank being connected thereto by a supply pipe 13 and. over flow return pipe'lg and the. earbureter by a pipe 14. The pump. is connected by a p 15 9 the m ust on c amb 9 he engine, such as. the opening for the prim} ing cub for the engine, as shown at 1 6.

The means to draw and deliver the fuel from the tank to the carhuret'er or engine is operable by the varying pressures in. the combustion chamber of the engine, such as during the powerand compression strokes, or the suction and exhaust strokes, of the engine piston, in theform'thereof shown in Figure 2, includes a reservoir 29.

The reservoir 29, is preferably. a cylindrical, drawn" metal" cup, in which. the. pumpingmechanism, axially located, said reservoir having an. outlet 34; to which the pipe, '14 leading to the carbureter is connected. The reservoirclosedbyabottom 1 5 piece 36 haying an annular flange 37 soldered or-brazed to the lower edge 35 of the receptacle. The top, bottom have central openingsv througl i which. the pum 17 extends and in which it issecured air tight, 2 as by soldering or. brazing.

The pump comprises a cylinder, 17' in which there is; mounted a reciprocable piston 18, said piston separating the. cylinder intoa. motive chamber-19 and a. pump cham- 125 ber 20. The' motive chamber has a-fmotive. fluid inlet 23 through the removable closure.

21 of the. cylinder 17' and to the threaded projection. of this. closure. 21,v is connected the pipe 15 whereby the motive chamber 1-30 cross-sectional area of the cylinder 4.00

times that otthe constriction, but it will be understood that this may be varied to suit the conditions and purposes in view.

The pump chamber 20 has an inlet 24-, connected through a coupling and pipe 13, with the tank 12, the inlet opening upward into the pump chamber 20 and being nor-. mally closed by an upwardly-opening grav- I ity-seated valve 26.

The piston 18 is usually formed to fit thepump cylinder 17 closely enough so that no packing is necessary, an easy sliding fit with a clearance of one to two thousandths of an inch bemg suflicient to operatively withstand the'pressures in the motive chamber, 19. l

prefer, however, to employ oil grooves 40 about 3 inch in diameter spaced one-eighth inch apart and if desired, the piston may be provided with a cup leather packing. The piston body is preferably made of great length as compared with its diameter so that there can be no tendency for itto become cooked in the cylinder even when reciprocating most violently.

The pump end or the piston is preferably formed with an outlet 27 for discharge of the pump fluid and the outlet valve 30 is preferably located in the piston for reasons c2;- plained above. A convenient way of forming the pumpend of the piston is to drill it axially from the lower end to a diameter suitable for the chamber of the outlet valve 30 with sufficient clearance for flow r'luid.

around the sides of the valve. Then the spring 33 and valve 30, which is preferably a ball, being inserted, a screw bushing 31 formed with a valve seat and port is screwed in behind the ball. Preferably a spring 33 is provided to press the valve 30 toward its seat; The upper portion of the outlet valve chamber 27 is provided with outlet ports 27 drilled through the walls of the piston. As these ports are in, and necessarily travel. with the piston, a wide annular groove 2'7 is formed outsidethe piston, the width of the groove being such that during normal operation, some portion of it will always register with ports 27 which are drilled through the wall'ofthe pump cylinder. preferably at a downward slant so that the discharge of the liquid into the reservoir will be downward. By varying the width of groove 27, the limit of the piston stroke may be controlled, since movement of the piston to a position where theports 27 are covered, cuts oi turther e.- cape of liquid from the pump cavit -J.

It will'be noted that in this piston, the

pumpin or liquid-sucking surface comprises the lower surfaces of piston 18, bushing 31 and ball 30, while the liquid expelling surface is the upper surface of groove 27 and the top oi drilled hole 27. Also that simi lar functions could be served by other constructions aFording the necessary relations of liquid sucking and expelling surfaces with interspace containing the pump chamber outlet and outlet valve.

The listen is yieldingly maintained toward the uppermost end of the cylinder 17 by a long spring This spring is compressed by the piston on the compression and z-plosion strokes of the engine cylinder and serves to return the piston when the pressure in the motive cylinder decreases during the exhaust and suction strokes.

During the pressure strokes of the piston of the engine, the pressure will be transmitted through the connection 15 to the motive chamber 19 of the pump cylinder 17, from the combustion chamber of the engine cylinder, and will be exerted on the end of the piston 17, and through the latter on the fluid in the pump chamber. This will seat the inlet valve 26 and unseat the outlet valve 30 thereby cutting off the tank and opening communication between the pump chamber 20 and the reservoir 29. During the suction strokes of the engine piston with the consequent reduction of the pressure in the connection l5 and in the motive chamber 19, the spring 43 will move the piston toward the upper end of the motive chamber, and, the valve 30 having automatically seated by gravity, inertia and spring 33, the return movement of the piston 18 will create vacuum in the pump chamber 20, thereby unse ting the valve 26 and drawingthe fuel from the tank 12, through the connection 13, into the pump chamber. This latter movement of the piston 18 may also be facilitated during the suction stroke of the piston of the engine by the creation of a vacuum in the motive chamber.

Where the speed oi? operation of the engine is fairly unirorm or is not too fast, as for instance, on certain types or stationary engines, the spring may be made strong enough so that the return stroke of the pump piston will always be completed.

For-the preferred use on automobile enhowevcr, the spring 43 is preferably made yielding enough to permit a substantial'pumping stroke even when the pressures in the engine cylinder are weak. as for instance, when idling with nearly closed throttie or when the engine is being cranked. Such a spring becomes progressively stiti'er when increasing engine pressures give longer outstrokcs of the pump piston. I have discovered, however. that this spring may he made more vielding and more sensitive for the light pressures, when employed in con junction with a supplemental stiffer spring 43 which, as will be seen from the drawings, is of substantially shorter length and range of action. With this arrangement, spring 43 maybe made only so stiff as is necessary to lift the load of gasoline in the supply line-at slow speeds, and spring 43 need not function at all when the pressures are low and the stroke is short; but when the motive pressures become more violent and the stroke longer, spring 43 will afford a supplemental increasing resilient restoring power additional to that obtained by the increasing compression of spring 43.

At the motive end of the piston is a bumper spring 44 of shorter length and range than those just described. It is interposed between the piston and the closure end 21 of the motive chamber, to prevent the upper end of the piston from striking a ainst the end of the chamber and making clicking or knocking noises. When it strikes the end of the chamber, it is compressed and its subsequent recoil and expansion assists the next out-stroke.

The reciprocation of the piston 18 synchronizes with the suction and compression strokes of the engine piston, and the stroke of the piston 18 is regulated in accordance with the pressure in the engine cylinder.

For instance, should the throttle valve for the fuel intake of the engine be closed with consequent low pressures in the engine cylinder there will be a low pressure in the motive chamber of the cylinder 17 and a short motion or out-stroke of the piston 18, and as the throttle valve for the engine intake is opened with the consequent increase of pressures in the engine cylinder, there will be a -.corresponding increase of the pressures in the motive chamber of the cylinder 17 and a longer out-stroke imparted to the piston 18.

It will be evident, however, that for use on an automobile engine, springs 43, 43* which will be yieldingenough to permitellicient pumping movement of the piston for the lower and medium pressures and speeds of the engine, will function somewhat differently when the engine is operating at high speed. Such a spring can complete the return stroke if the motive pressure is relatively low so as to give short out-strokes or if the speed of the engine is slow so as to give the spring time to do its Work. But where high engine pressure, giving a: long out-stroke, is combined with high engine speed giving a short time for the spring to work, there will be only time enough for a portion of the return stroke, the slower final part of said stroke being cut shortby a succeeding explosive pressure. Consequently, with increasing pressures and speeds, the piston continues to reciprocate in response to the variations of pressure, and the length of the strokemay be approximately the same or may be less, but the range of stroke tends to shift toward the spring to a position where the spring operates under a umioriniy 4 increased range of maximum and minimum pressures. I

There ma be a sim lar e fiect due to the above-descri ed constriction of the inlet ency becomes more pronounced with i ing speeds of the engine. Hence, though the pressures in the engine dont i nne' to alternate between pronounced and high pressure, at high speeds the pressur on the pump piston tend to pulsating, that is, they are above atmosphere even during the vacuum strokes of the engine.- This pulsating excess pressure at high also tends toforce the pump piston com-re the spring thereby compressing the until a position is reached where the springs under a continuous minimum oompmssloir' equal to the continuous minimum pressure in the motive chamber. y

The piston continues to reciprocate in response to*the variations of pressure, and the: length of the stroke may be approximately the same or may be less, but the'rangc of the stroke is shifted enough to malwthe spring return strokes more powerful and quicker acting. I

Making the spring 423' of great and providing a long clearance'or pumpiatg'spate in the cylinder, as shown in the drawings affords a considerable range for the above; described shift of position of the stroke of the piston and corresponding increase" of spring stiffness. It is one good method at rendering the device automatically sjelteao' commodating for the wide range of speeds and pressures practically necessary in the operation of automobile and similar ternal combustion engines; able range of engine speeds the length at the: stroke will be determinedby di'flerencen of pressure during each cycle of explosibn,

exhaust, suction andcompress'ion in" the en 7 gine, changes in the speed being: taken care 9. For a consiidhwof to a large extent by the automatic shift of the position of the stroke to a position where the spring is quicker acting.

The spring 44 on the opposite end ofthfl'. piston, is of shorter length and shorter range of action than spring 43. It func-w tions only when conditions are such ast'q permit completere'turn stroke of the pistonon each suction stroke of the engine and'this, will be evident, is at the lower enginespecds and pressure, particularly at times when the speeds and pressures are low enough hr astablishing. a vacuum, or below-atmqsplicrc, pressure in the motive chamber of the pump) by the suction stroke of the piston. Then,

as soon as the suction is relieved, the expansion of spring 44 initiates and assists the subsequent expansion stroke. In this way the short spring 44 acts during times of alternating suction and pressure on the piston, in a manner somewhat analogous to the action of spring 44 during times of continuous pulsating pressure.

The inlet and its valve and the outlet and its valve have peculiarities which in combination contribute to the efficiency of the pump, especially when used for its preferred purpose as a fuel pump on an automobile engine. The explosion strokes in any one of the cylinders of an automobile engine will vary from say 3 or 4 per second for idling, up to say 40 or 50 or more per second for high speed operation. Obviously, in such operation, any delay, even for a small fraction of a second, in the closing of the inlet valve will permit appreciable slip or backflow of liquid to the tank.

The effectiveness of inertia in seating the outlet valve under such conditions has been explained above. The cooperating inlet- "valve 26 is a free, gravity-seated. ball. It is a simple and very effective means of getting the quick, free, low-resistance opening of the inlet which is very desirable at all times, and particularly so when the supply pipe is empty andthe gasoline must be lifted by first pumping air; but the ball form and absence of spring pressure tend to make it slow-closing. Hence the outlet 27 is of smaller diameter and of greater fluid flow resistance, than the supply inlet 24; also the piston outlet valve is forced to closed position by spring 33. The smaller size of the outlet port and the spring pressure on the valve both contribute to making the outlet of higher resistance than the inlet. This gives a back-pressure on the outlet, with the result that the high speed movement of the piston under the explosive pressure from the engine, taking effect on incompressible liquid, piles up a suflicient back-pressure on the inlet valve to force it tight down on its seat at the very beginning of the expelling stroke of the piston.

With the above described perfections of construction, relative arrangement and pro portioning of parts, it will be possible for one skilled in the art to attain any desired degree of efliciency in pumping either for intermittent or continuous supply under any and all practically possible conditions. VV'here the conditions are not exacting, as for instance, where there is reservoir capacity sufficient to bridge over the short periods of inaction of the pump or where the engine is of relatively uniform speed or low speed for instance a stationary engine controlled by a hit and miss governor, it will not be necessary to employ any more of my novel features than may be necessary for the purpose in view. An important point, however, is that even though the conditions be "extremely exacting, my invention provides means whereby the pump may be made continuously acting. Thus, for instance, on a variable-throttle, variable-speed automobile engine, the pump may be made to operate on merely cranking pressures and suction in the engine and may be made to pump when the supply line is empty so that, at first, air' must be pumped in order to apply suction to raise the liquid from the rear tank.

A most important feature of my invention is that having achieved a continuously and adequately operable pump, I utilize it so as to get rid of many causes of trouble and danger commonly found in all prior devices of this type, including the following:

The continuously acting pump renders large reservoir capacity unnecessary and this element of the device may be reduced to a small, inexpensive pressure chamber of such capacity as may be necessary to steady the flow of liquid from the pump to the carbureter. Floats and valves and reservoir vents for controlling the level of the liquid in the reservoir with all the attendant expense, danger of flooding, fire hazards and gasoline waste may be completely eliminated.

lVhile this apparatus, and particularly certain features thereof, are of considerable novelty and importance independently of any special refinements in the method of oporation, one of its important advantages is its capability of being proportioned and arranged for operation by a special-method involving peculiar advantages.

F or instance, the natural way to design the device would be to have the pump designed for pumping only a small surplus above the maximum demands of the carburetor and the overflow return pipe designed for a drainage capacity large enough to drain off this surplus thereby keeping down the liquid substantially to the level of the outlet, Perfect operation by this method requires a large drain pipe which is expensive and cumbersome. On the other hand, if the drain pipe is designed of a size only suliicient for drainage of the average surplus liquid, it will be flooded at times when the Under such conditions, it the overflow pipe is not filled with a solid column. of

iquid, the work required of the pump will be widely variable. When the automobile is on a level, the work of the pump will be lifting'liquid say 18 inches or perhaps 3 feet at the most. ,Going up a steep grade, Y

liquid will accumulate in the reservoir and i will rise above thetop of the stand pipe until an internal pressure is developed sufii- I cient to blow the excess out through the regravity.

turn pipe with little orno help from gravity; This variable shifting of the load of the pump from all in the lift pipe to part or all in the drainage pipe is attended with notable variations in level oi the liquid in the reservoir as well as varlations 1n the in tcrnal pressures of the air trapped in the top of the reservoir. This is at its worst where the automobile is alternately proceeding up and down steep grades, so that the back pressure of the full drainage pipe going down hill is followed by a substantial suction due to a sudden reversal of inclination of the filled overflow pipe upon going up hill and the resulting emptying of said pipe by As contrasted with either the small-surplus-aniple-drainage method, my invention contemplates making the pump oi such large pumping capacity and the overflow return pipe of such small size that under normal average conditions of speed, load and throttle opening, the supply will exceed the naximum demands of the carbureter plus the gravity drainage capacity of the return pipe, and will afford a surplus suilicientto swamp the outlet and keep the return pipe filled with a solid column of the liquid, duringnormal operation. The over-supply first swamps the outlet and then the liquid goes on risingto a height predetermined by the size of the compression space in the topo't the reservoir and by the back pressure due to the under-size oi the overflow return pipe, The risingpressure in the top of the reservoir assists gravity in forcing the liquid through the return pipe at ii'icreasing speeds thereby increasing the capacity of said return pipe to the extent required 1?) take care of the over-supply. up

By this method, the normal or average conditioner operation of the pump and the internal pressures in the reservoir, becomes approximately constant. When the device it rest, the liquid can drainofi' to the exact level of the overflow 'stand pipe and the loadon the pump.

any excessive internal pressure or vacuum can be relieved by vent to the atmosphere through the rear tank. Upon startlng f the pump, however, the over supply of liquid submerges the outlet and fills the return pipe with a solid column of liquid, 3

pump comprises two continuous loads which may be made normally equal if desired.

These two loads are the suction load through the lift pipe from the tank, and; the backpressure or force-pump lead through the return pipetothe tank. The, suction or lift pipe load will be the frictional resistance plus the gravity resistance or staticheadof ,the lift column inthe Supply pipe, whileitga i i Te back-pressure or force-pump .load wr M trlction minus the static head ofvthe drop column through the return pipe, That is to say, the gravity componentof the pump.

load is measured by the difference in the static heads, and when the returnpipe is lrept full this is merely the vertical distance from the surface of the liquid in therear tank, up to the level of thereturn outlet in the top thereof.

used on an ordinary automobile, as indicated in Figure 1, any changes in the inclination in the automobile will not materially change i St iLQQ if th automobile goes up a steep graddsothat the pump has to lift the liquid against a static head 3 feet greater than before, the return pipe corelatively will have the same increase of static head applying a correspondingly increased suction decreasing the back pres sure on the pump. I If, on the other hand, the automobile goes down a steep grade'thereby reducing the work of pumping into the reservoir, the equal and opposite (mange of the-static head in the return line will increase the back-pressure load by substantially thefsame amount that the suction load has been decreasedwin the supply line. i i V Thus the continuous force feed return against back pressure, ensuring a, normally full return pipe,'makes the work of the pump approximately independent fol the angle of upward or downward pitch of the car. Moreover, the work of the pump being thus rendered approximately constant,it is a simhis, distance is small and substantially In this situation, the total load on .th

ple matter to proportion thepar ts so that the pressure in the pressure chamber will be practically constant at say one-half pound to onepound per square inch. This is a desirable pressure to have for supplyingtlw reservoir of a carbureter because itis small enough to be easily controlled by th e ordinary valve and float; of the carbureter bowl and yet substantial enough tobeneficially supplement gravity in promp ly upplying the liquid to said bowl when said float opens said valve.

The liquid level and internal pressures are kept practically constant. notwithstanding the action of the gasoline in giving off and absorbing air and gases under varying practical conditions of operation because the overflow return pipe has its outlet into the tank at a point above the highest level of the liquid when the tank is full. This space is kept at atmospheric pressure by a suitable vent in the top of the tank. Hence the hermetically sealed chamber will vent through the tank and can blow-off or such air every time the liquid falls below the open end of the stand-pipe 70. This can occur every time the engine is stopped, and could also occur during running provided the internal pressure got high enough to blow out the liquid through the return pipe faster than the excess accumulates.

rection assisting gravity in discharging liquid at an increased rate through the re turn pipe, but they also work backward imposing aback pressure or load opposing expulsion of the liquid from the pump chamber and hence to that extent counterbalane ing the motive pressure in the motive chamber of the pump. Consequently when these internal pressures are made continuous, as by my above described method, they also tend to be self-governing for constant pressure even against considerable variations of operating conditions, but when they are sometimes present and sometimes relieved or even reversed to a vacuum, as they are when not operating according to my said method they become a cause as well as an effect of extreme irregularity in the functioning of the de vlce.

I have found that the above described direct connected pump will operate for long periods of time without clogging of the pressure conduit 15 or the constricted passage 23 provided there are no leaks in the pipe or its connections such as would permit hot gases from the engine to findtheir way to the. pump connectlon. However, as shown in Figure 2, I prefer to guard against all possibilities of clogging, by having the constriction 28" in alignment with the axis of the pump cylinder and providing the piston with an axial projection 80, having a reduced cleaning stud or needle 81, of such length that it will project through the constriction whenever the piston reaches its normal initial ,position either during its reciprocatory functioning above described or when it comes to rest after the engine stops.

In practical operation, it is important to have the location of the pump cylinder within and in contact with the body of gasoline and to have the normal level of the latter maintained substantially above the levet of the pump outlets. Thus designed, the gasoline keeps the pump cool thereby dissipating the unavoidable heat transmitted through the pressure connection with the combustion chamber of the engine which would otherwise tend to vaporize the gasoline in the pump, As it is, the pump chamber is kept flooded and primed with gasoline substantially free from vapor and hence in condition for immediate effective pumping operation.

I claim:

1.. In a fluid supply system, an internal combustion engine provided with an intake and carbureter and a fuel supply tank vented to atmosphere. in combination with a closed reservoir having a pipe to feed fuel to the carbureter; a fuel supply pipe and continuously operating pump drawing gasoline from said supply tank and discharging it into said reservoir at a rate suflicient to cause pressures higher than atmosphere in said reservoir; a stand-pipe overflow and a return pipe of smaller cross-section than said supply pipe communicating with said supply tank above thehighest level of liquid therein when the tank is full and operating to vent the upper portion of said reservoir through said tank.

2. In. a fluid supply system, an internal combustion engine provided with an intake and carburetor and a fuel supply tank vented 'to atmosphere, in combination with a closed reservoir having a pipe to feed fuel to the carbureter; a fuel supply pipe and continuously operating pump drawing gasoline from said supply tank and discharging it into said reservoir at a rate sufiicient to cause pressures higher than atmosphere in said reservoir; and means for periodically venting the compression space in the top of the closed reservoir through the empty portion of said supply tank.

3. An internal combustion engine provided with an intake and carbureter and fuel supply system therefor including a supply tank vented to atmosphere, in combination with closed reservoir having a pipe to feed fuel to the carbureter, a supply line and continuously ooerating pump drawing fuel from said supply tank and discharging it into said reservoir and a stand-pipe having its intake a substantial distance above the level of the pump discharge and a return pipe leading to said supply tank above the highest level of liquid therein when the tank is full.

i. A structure adapted to operate at varying inclinations and having secured thereon, a variable-throttle, variable-speed. internal combustion engine, a vented fuel supply tank located away from the engine so that its level is varied with reference to the fuel intake of the engine by the varying inclinations of said structure, in combination with a combined reservoir and pump. a conduit leading from below the level of liquid in the tank to the pump and from near the bottom of the reservoir to the fuel intake, a return conduit leading from the reservoir to the tank, discharging into the tank at a pointabove the level of the liquid. therein, said pump having a pumping element, one face of which is directly connected with the pres sure chamber of a cylinder of said engine and continuously actuated in one direction by the varying pressures from the cylinder and in the other direction by a spring, the other face of said pump element being in operative relation to a pumping chamber with suitable inlet and outlet passages and valves for drawing liquid from the tank and discharging it into said reservoir, said pump being designed and arranged to pump and expel any gaseous fluids thereby normally to operate on an incompressible body of liquid in the pump chamber, said reservoir being sealed against inlet or escape of liquid except through said conduits, and said pump having at all times a pumping capacity in excess of the combined maximum demands of the carbureter and the gravity outlet ca pacity of the return pipe thereby continuously operating by pressure to forcibly expel surplus fuel through said return pipe, for the purpose described.

A structure adapted to operate at varying inclinations and having secured thereon, a variable-throttle, variable-speed internal combustion engine, a vented fuel supply tank located away from the engine so that its level is varied with reference to the fuel intake of the engine by the varying inclinations of said structure, in combination with acombined reservoir and pump, a conduit leading from below the level of liquid in the tank to the pump and from near the bottom of the reservoir to the fuel intake, a return conduit leading from the reservoir to the tank, said pump having a floating piston, one face of which is connected with the pressure chamber of a cylinder of said engine and continuously actuated in one direction by the varying pressures from the cylinder and in the other direction by a spring, the other face of said pump element being in operative relation to a pumping chamber with suitable inlet and outlet passages and valves for drawing liquid from the tank and discharging it into said reservoir, said pump and piston being designed and arranged to pump and expel any gaseous fluids thereby normally to operate on an incompressible body of liquid in the pump chamber.

6. A structure adapted to operate at varying inclinations and having secured thereon, a variable-throttle, variable-speed internal combustion engine, a vented fuel supply tank located away from the engine so that its level is varied with reference to thefuel intake of the engine by the varying inclinations of said structure, in combination with a combined reservoir and pump, a'conduit leading from the reservoir to the tank; said combined reservoir and pump including a vessel adapted to be secured in upright position, a closure for said vessel, a tubular member secured in vertical position in said vessel and having inlet passages from the exterior through its up er and lower portions respectively, a combmed motor and pump element actuated by pressure applied from said source through the upper passage, the intake of said pump being through said bottom passage and the dischargebeingthrough a valved outlet through said piston into said vessel.

7. A structure adapted to operate at varying inclinations and having secured thereon, a variable-throttle, variable-speed internal combustion engine, a vented fuel supply tank located away from the engine so that its level is varied with reference to the fuel intake of the engine by the varying inclinations of said structure, in combination with a combined reservoir and pump, a conduit leading from below the level of liquid in the tank to the pump and from near the bottom of the reservoir to the fuel intake, a return conduit leadin from the reservoir to the tank; said com ined" reservoir and pump including an upright, pressure 01')- erated pump including a floating piston having its downward stroke non-positively actuated by pressure variations from the coinbustion chamber of a cylinder of said engine and its return stroke assisted by' a spring, the pump surfaces of said piston constituting the top of the pump chamber; inlet and outlet passages and check valves therefor controlling the flow of fluid; said inlet and inlet valve opening upwardly into the lower part of said pump chamber; said outlet being through said pump surface of the piston and said outlet valve being located in the piston and arranged to move in alignment with the reciprocating movements of the piston, so that the inertia of the valve operates to assist the lifting and seating movements thereof; and a yielding spring pressing downwardly on said outlet valve, for the purpose described. v

8. A structure adapted to operate at varying inclinations and having secured thereon, a variable-throttle, variable-speed internal combustion engine, a vented fuel supply tank located away from the engine so that its level is varied with reference to the fuel intake of the engine by the varying incline-- tions of said structure, in combination with a combined reservoir and pump, a conduit leading from below the level of 'liquid in the tank to the pump and from near the bottom of the reservoir to the fuel intake, a return c pit leading from the reservoir to the tank, said pump including a floating piston having a working portion in operative relation to a pump chamber and a motive portion in operative relation. to a pressure chamber of a cylinder of the engine; and inlet and non-return valve therefor control ling free, low-resistance flow of fluid into said pump chamber; an outlet and nonreturn valve controlling a relatively high resistance flow of fluid out of said pump chamher.

9. A structure adapted to operate at vary ing inclinations and having secured thereon, a variable-throttle, variable-speed internal combustion engine, a vented fuel supply tank located away from the engine so that its level is varied with reference to the fuel intake of the engine by the varying inclinations of said structure, in combination with a combined reservoir and pump, a conduit leading from below the level of liquid in the tank to the pump and from near the bottom of the reservoir to the fuel intake, a return conduit leading from the reservoir to the tank, said pump including a floating piston having a working portion in operative relation to a pump chamber and a motive portion in operative relation to a pressure chamber of a cylinder of the engine; and inlet and non-return valve therefor controlling free, low-resistance flow of fluid into said pump chamber; an outlet and non-return valve controlling a relatively high resistance flow of fluid out of said pump chamher, said pump being designed and arranged to pump and expel any gaseous fluids thereby normally to operate on an incompressible body of liquid in the pump chamber, said reservoir being sealed against inlet or escape of liquid except through said conduits, and said pump having at all times a pumping capacity in excess of the combined maximum demands of the carbureter and the gravity outlet capacity of the return pipe thereby continuously operating by pressure to forcibly expel surplus fuel through said r turn pipe, for the purpose described.

10. In liquid feeding means for internal combustion engines, the combination with an internal combustion engine and a liquid supply tank, of a conduit and pressure actuated pump interposed between the tank and the intake of the engine; said pump including a cylinder and a piston to reciprocate in said cylinder and separating the cylinder into a pump chamber and a motive chamber; a port and conduit connecting the motive chamber with the engine cylinder; a spring in the pump chamber yieldingly pressing said piston toward said port; said port being in alignment with the axis of the piston and said piston having a clearing needle adapted to enter aid port when the piston is in its rcarmost position.

11. In liquid feeding means for internal combustion engines, the combination with an internal combustion engine and a liquid supply tank, of a conduit and pressure actuated pump interposed between the tank and the intake of the engine; pump including a cylinder and a piston to reciprocate in said cylinder and separating the cyl inder into a pump chamber and a motive chamber; a port and conduit connecting the motive chamber with the en 'ine cylinder; a spring in the pump chamber yieldingly pressing said piston toward said port; said port being in alignment with the axis of the piston and said piston having a clearing needle adapted to enter said port when the piston is in its rearmost position, an upwardly opening valve controlled inlet into the pump chamber, from the tank; a pump outlet opening upwardly from the uppermost portion of the pump chamber; and anon-return valve adapted to check reverse flow of liquid through said outlet during the lifting stroke of said piston.

12. The method of maintaining a substantially constant pressure fuel supply to the carbureter of an internal combustion engine from a supply tank of variable level with reference to said carbureter, through a pumping circuit including conduits from below the level of the liquid in the supply tank to a point above the level of said liquid and an intermediate sealed reservoir having a feed connection to the carbureter, which method consists in continuously applying a varying gas pressure of the engine, non-posi tively forcing through said conduit into said reservior a supply of fuel greater than the combined withdrawal capacity of the carbureter and the gravity-flow capacity of the return portion of the pumping circuit, thereby maintaining under average conditions a gaseous pressure in said reservior, operating by back pressure on the pressure actuated pump and by forcing pressure on the return conduit so as to have a self-regulating constant pressure tendency and thereby affording a greater fuel supply and a wider range for abnormal operation under abnormal conditions.

13. The method of maintaining substantially constant pressure fuel supply to the carbureter of an internal combustion engine from a supply tank of variable level with reference to said carbureter, through a pumping circuit including conduits from below the level of the liquid in the supply tank to a point above the level of said liquid and an intermediate sealed reservoir having a feed connection to the carbureter, which method consists in forcing through said con- (luit into said. reservoir a supply of fuel greater than the average combined withdrawal capacity of the carbureter and the gravity flow capacity of the return portion of the pumpingcircuit thereby normally maintaining a solid column of liquid throughout the pumping circuit and an approximately constant load on the pump independently of the level of the tank with reference to the carbureter. 1 i0 Si ned at New York city in the county of New York and State of New York this 18 day of March, A. D. 1920.

WILLARD I. TWOMBLY. 

